My GP puppy, approx. 10 weeks old, became very lethargic Thursday evening and would not eat. We kept her inside and the next morning were greeted with the most awful foul smelling yellow diarrhea all over the floor of the room she stayed in (I still haven't gotten rid of the smell). DH rushed her to vet. Vet could not get a stool sample but looked at her gums which were light and thought she had a worm issue and prescribed Panacure which we gave her yesterday and this mornng. This morning she seemed better - was up and moving around. Tonight she's vomiting clear watery vomit (with some grass in it) and has the awful foul smelling yellow diarhhea. The smell is something I've never encountered and can't even describe how awful. We called the vet and poor thing hid in her laundry room to talk to us because it was after 10 p.m. and the Easter Bunny had already come to her home and she didn't want to wake her kids. She's a great vet. After describing tonight's events, still won't eat, very lethargic but will drink, and that awful diarreah, (but NO blood in it), vet thought Cocci and prescribed Sulmet which we had on hand. BUT...the more I'm reading on-line, the more it points to Parvo and one article even said that since it's often mistaken for Cocci that giving sulfa drugs worsens the dehydration and can cause death. It also seems there is no cure for Parvo, just try and keep the puppy alive and from dying of dehydration. The vet said since she was still drinking to add the vitamin/electrolytes to her water (again on hand for chickens). Does anyone have experience with a puppy with Parvo and/or Cocci and/or Hook Worms. I'm so worried about my little "Polish Bear" - she just lays there and seems to have lost weight almost over night. But I also have her brother, who isn't showing any signs of being sick but I'm worried either way he will catch what she has. Vet told us to give him the Sulmet and Panacure as well.